The invention relates to a filter element, in particular, an interior filter for filtering air for the interior of a motor vehicle.
Such a filter element serves for filtering fluid flows or gaseous media, for example, for filtering an air flow that is supplied to the interior of a motor vehicle. Even though the present invention can be used in connection with any filter element, the present invention as well as the problems to be solved by it will be explained in the following in connection with a filter element for filtering air for the interior of a motor vehicle. Such filters are referred to in the following as motor vehicle interior air filters or interior filters as well as cabin air filters.
In view of the increasing air pollution, in particular in metropolitan areas, in connection with the use of modern air conditioning devices, it is desirable and also necessary to purify by suitable filters the air that is supplied from the exterior to the interior of a motor vehicle and, in the process, conditioned or air-conditioned. For example, particle filters or odor-eliminating filters or their combinations are suitable for this purpose; the filters should remove or absorb as much as possible of suspended solids, particles and odors contained in the ambient air. Such filters for filtering air for the interior of a motor vehicle are generally known in a plurality of embodiments and variants so that their configuration and function will be explained only briefly in the following.
Since the efficiency of filters depends in particular on the size of the surface area of the filter through which the air passes, zigzag-shaped folded filter media, also referred to as pleated filter media, are utilized primarily in the case of motor vehicle interior air filters. By means of folding of the employed filter medium and depending on the fold height, the fold spacing, and the degree of compression of this accordion-like filter pack of the different fold sections of the filter medium, an enlargement of the filter surface area through which the air flow passes can be achieved. In order to be able to handle such filter elements with zigzag-shaped folded filter media better, in particular during mounting, frequently reinforcement elements are provided on the sides of the filter element along the filter pack of folded medium. These reinforcement elements serve for lateral fixation and stabilization of the zigzag-shaped filter medium and are usually attached by means of a suitable adhesive to the lateral edges of the fold pack. In this way, the filter element with strip-shaped reinforcements provided on the folded longitudinal sides can be inserted in a simple way without damaging it into a housing of a filter assembly or a matching filter receptacle, for example, a filter housing or an air conditioning device of a motor vehicle.
Filter elements of this kind are disclosed e.g. in German patent applications DE 102 31 696 A1 and DE 102 41 748 A1.
In addition to the requirement of stability, the filter elements for filter inserts must also seal-tightly connect to the edge areas of the corresponding housings so that the air to be filtered flows substantially completely through the filter medium or the fold pack and does not flow past it.
It is moreover desirable that these filter elements, in addition to a simple mounting-technological handling, should also be inexpensively and therefore should be producible with regard to manufacturing technology in a way that is as simple as possible. In this connection, it is also desirable that as little as possible of the filter material, e.g. non-woven filter material, is required.
Given this background, the present invention has the object to provide an improved filter element that has, in particular in the edge areas, a sufficient stability as well as a seal-tight connection to the filter housing.